Hi guys. Been a while since I posted on here. I just hacked my CSA Derringer to use a 128meg 72pin SIMM. Thought I'd do a quick write-up for other Derringer owners.

1.)Remove Derringer from the machine.

2.)Remove 68030 from socket (you will be soldering to the back of the 68030 socket pins, so you wouldn't wanna risk heating on the CPU, itself.. Anywayze.. Remove it..

3.)Remove any SIMM that may be in the SIMM socket.

4.)Find U17 on the top side of the board, its located in between the CPU and the SIMM.

5.)Lift pins 12, 13, and 14 of U17 and solder 3 wires, one to each lifted pin. Make these wires about 10-15cm long for now, and carefully run them through the hole (see photo).



6.) turn the derringer board upside down and find pin 29 of the SIMM socket.

7.) Get a 27ohm resistor and solder one leg of it to pin 29 of the SIMM socket.  Solder the other leg of the resistor to the wire that goes to pin 12 of U17.

8.) Solder the other 2 wires that go to pins 13 and 14 of U17 to pins A4(A28) and B4(A29) of the back of the 68030 socket.



9.) Reinstall the 68030 CPU and SIMM back into the Derringer's sockets.

The SIMM you need is actually 32meg x 32/36 (128megs total).

From the factory, the Derringer can use SIMMs of up to 8meg x 32/36 (32megs total).
Adding the RA11 address line gets us 4x more memory.

I got my 128meg SIMM from Mech of a4000t.com


10.) Install the derringer in the AMIGA.

11.) Boot up the AMIGA. If it doesn't boot, you screwed something up and it isn't my fault.

12.) Get this archive: http://aminet.net/util/boot/addmem301.lha

13.) Uncompress the archive and copy the addmem command to your c: directory on your system boot drive.

14.) Add the following 3 commands to your S:Startup-sequence right after the D3 command. Here's what mine looks like:

c:D3 >NIL: dram drom -mv -ms
c:Addmem >NIL: $18000000 $1A000000 32bit
c:Addmem >NIL: $28000000 $2A000000 32bit
c:Addmem >NIL: $38000000 $3A000000 32bit
c:caches >NIL: +i +d

The D3 command is the normal Derringer command that adds the 32megs, relocates the ROM & vector tables, etc. to 32bit fastram.

The Addmem command here is adding 3 additional 32meg chunks of 32bit ram to the OS's free memory list, at the specified ranges.

The caches command just turns on the 68030 instruction & data caches.

Ok. So that's all there is. It works like a charm for me. If it works for you, great. If not, it ain't my fault.

"You mess with your hardware, you take your chances."

Seeya!

Yeah, Martin, I'm still in Houston. PM me.

Just so happens I have a spare 128MB SIMM on-hand.  I will definitely have to give this a try.  Thanks.

Mine is in an A500, and the whole arrangement has a keyboard laying right on top of it.

Hope this helps.

Yes, this helps a lot.
My derringer is the 50mhz version. and is sitting in an A500+
I have some problems now with space inside the case. as i have a indivision installed. the two boards collide and argues about some space.

I am looking for ideas to solve the problem. (if anyone got any good ideas I'm listening) And i am on the look for any cpu slot ide controller capable of handling a (or two) CF card(s) for HDDrives.

Yes, this helps a lot.
My derringer is the 50mhz version. and is sitting in an A500+
I have some problems now with space inside the case. as i have a indivision installed. the two boards collide and argues about some space.

Here is how mine looks



Cant remember what I did to make the indivision ecs fit under it. probably lowered the socket, shortened the standoffs, and relocated any tall components to the other side of the A500+ motherboard.

I was working on something like this,but not for this card. It was a single sided 128MB or 256MB per simm (custom memory module) but I abandoned it about 4 years ago for speed 28ns.

EDIT: release of 40n EDO memory chips cancelled.

I will definitely try it. Now i am using 64MB SIMM which D3 detects as 16MB.
The system is stable with it.

Do you think I will get 64MB with this hack?

The SIMM is single sided with 8 chips on it. The chips are MT 4LC16M4H9-5D.

http://pdf1.alldatasheet.net/datasheet-pdf/view/75891/MICRON/MT4LC16M4H9DJ-5.html

Well, it depends actually on how it is getting the 16meg. But like I said, there's no reason not to perform the mod. It won't change the way your derringer works with existing SIMMs. All it does is open the possibilities of using SIMMs that have a full 12bits of base addressing.

Now back to the question of the RAM banking. Best case scenario, you could try several ranges and see which one works.

With a single sided SIMM I would *THINK* that its only using 2 RAS signals, but seeing full 11bits of base addressing and so it's getting 2 banks of 8megs. If that is the case, after the hardware mod is done, you should be able to get 2 banks of 32megs each by doing something like:

Addmem $08000000 $0A000000 checkmem 32bit
Addmem $18000000 $1A000000 checkmem 32bit

-or-

Addmem $08000000 $0A000000 checkmem 32bit
Addmem $28000000 $2A000000 checkmem 32bit

If the simm is wired differently, it could work with the following and get 4 sections of 16megs:

Addmem $08000000 $09000000 checkmem 32bit
Addmem $18000000 $19000000 checkmem 32bit
Addmem $28000000 $29000000 checkmem 32bit
Addmem $38000000 $39000000 checkmem 32bit



The datasheet you linked shows that those chips do have the A11 address line, so I would guess one of the first two scenarios to be the case.

When testing, disable D3 in your s:startup-sequence, so that no 32bit fastram is added to the system at bootup. Then, open a shell and try the above Addmem commands with the checkmem option invoked. If any section of ram isn't going to work, it will return an error message within a few seconds. If it doesn't, the system will appear to be locked up while it tests that section of RAM for several minutes, but eventually, it will return you to the AmigaDOS prompt and add the ram to the system (you'll see "other memory" increase at the top of the workbench screen.) After you've done all your testing, reenable D3 in the s:startup-sequence, plus add an Addmem command for each additional ram bank that D3 doesn't find, and this time, no checkmem option. (D3 "finds" the first bank, located at $08000000)

Hope this helps. Good luck![/b]